A Boost at the Border
Video analytics enhanced as perimeter security application
- By John Monti
- Mar 01, 2008
Mention border security, and
you might imagine the intersection
of two countries, or
perhaps the border separating
government facilities from private land.
But border security also can be defined as
perimeter security, which expands the concept
to encompass walls, fences, roads and
other perimeters around businesses,
schools, prisons, utilities, research facilities,
and other properties and buildings.
Because it is physically impossible to
watch every foot of perimeter and border
fencing or walls all the time, increasingly
the security function falls to cameras. In
the beginning, these cameras were primarily
static, analog devices, purchased inexpensively
and in large volumes to monitor
long perimeters. Besides their cost-effectiveness,
they were valuable because they
let security officials look back at recorded
footage following an incident to try to
piece together—from the usually lowquality
images—what happened.
While more expensive than the masspurchased
analog cameras, modern digital
video cameras offer rich functionality to
improve security functions. In fact, the
advent of digital video cameras, equipped
with video analytics technology, promises
to turn security cameras from passive,
backward-looking devices into intelligent,
active partners in helping prevent incidents,
as well as providing compelling evidence
after the fact. The success of video
analytics software, in turn, depends largely
on the quality of the video picture it has to
work with.
Special Challenges
Borders and perimeters may vary in size,
structure or purpose, but they share certain
challenges when it comes to security and,
specifically, the use of video cameras.
Almost all border and perimeter security
takes place outdoors, so cameras must
be weatherproof and tamperproof. That
often requires enclosures appropriate to the
site where they are installed. Also, effective
border and perimeter security systems
must be able to distinguish between potential
intruders and small animals entering
the field of view, and they must deal effectively
with natural elements such as trees,
shadows and insects on the lens.
The cameras and all the components
inside—including the image sensors, video
processing chips and other electronics—
must withstand temperature and humidity
extremes. This might be sweltering summer
heat or freezing, icy conditions. As a
result, rugged design is important.
Because they are installed and expected
to work 24 hours a day, the cameras and
lenses must provide the appropriate sensitivity,
adaptability and reliability to capture
useful images in a variety of challenging
lighting conditions. They must have a
wide dynamic range, which is the ability
to maintain consistent image quality and
accurate color in high-contrast scenes,
such as bright light and deep shadow,
simultaneously.
One major challenge of border and
perimeter security is ensuring sufficient
camera coverage. With today’s cameras,
this means not only enough cameras
mounted in the right locations, but also
sophisticated video analytics software that
dramatically improves the security function
at borders and perimeters.
Amplified Capabilities
Video analytics technology has the potential
to revolutionize how the security
industry monitors borders and perimeters
from a security guard function into an
automated task.
Traditionally, the primary role of cameras
in border and perimeter security applications
has been to provide security personnel
with accurate and rapid assessment
of alarms. Perimeter alarm systems can use
buried, fence-mounted or microwave
detection systems, among others. The camera’s
job is to provide high-quality images,
both day and night, in a variety of lighting
and weather conditions.
Video content analysis improves the
task of security cameras by providing specific
and timely alerts to security personnel,
based on the camera images. As such,
the video analytics system augments the
detection function of the perimeter alarm
system instead of simply operating alongside
it.
For instance, video analytics software
can instantly detect and record if a person
enters a secure area or if an unauthorized
person tries to cross a perimeter to the
other side, and then spur action based on
these observations.
Selection Factors
Regardless of camera type, factors such as
camera coverage, image quality, wide
dynamic range and broad coverage of large
areas will be important for border and
perimeter security.
Ideally, video analytics is embedded
into the camera, operating at the network
edge. Locating the video analytics at the
edge eliminates the need to transmit copious
data from the cameras to a central
monitoring facility, which can lower the
infrastructure costs and make many installations
more feasible. For example, it provides
an attractive practical alternative to
trenching fiber-optic cables across remote
desert stretches of the U.S./Mexico border.
This edge-based approach creates a
scalable and cost-effective system, with
lower latency between real-world events
and alerts to security staff. Accurate rules-based alerts provide low nuisance, such as
decreased false-positive alarm rates, and
can shorten response times. Rules can
specifically identify the location and
behavior of people, vehicles or objects relative
to defined areas, and easy-to-use filters
are available to exclude alarms caused
by nuisance factors such as small animals,
rain, snow or falling leaves.
In addition, modern video analytics
software is able to direct a PTZ camera to
remain trained on a suspicious person or
vehicle until security personnel can be
deployed. What’s more, some advanced
video analytics solutions can automatically
track an intruder from one camera to another.
This can be accomplished using either
fixed or PTZ cameras with hand-off capabilities
that enable multiple cameras to
track, for example, a person running along
a fence or a vehicle crossing into and
through a restricted area.
Some video analytics applications
include a GPS component that is automatically
tied to longitude and latitude, which
enables the camera to know where it is
geographically aimed. These GPSequipped
camera systems can thus produce
geo-registered targets, letting security personnel
know precisely where to respond to
an alert.
The cameras used for border and
perimeter security should not only meet the
security needs of the site in question, but
they also must be compatible with existing
or planned video management, access control
and alarm systems.
A camera’s ease of use while on-site
can make the difference between a smooth
and a rocky installation process. As an
example, Lumenera’s Pixim-powered
Li045C-DN intelligent camera—with
OnBoard embedded video analytics software
licensed from ObjectVideo—not only
addresses the special requirements of IP
cameras, but also includes an analog output
for use by CCTV installers. This feature
allows the installer to mount and focus the
network camera via a compact, portable
flat-panel display or CRT without worrying
about the network configuration, having a
computer present or contacting a control
room by phone or radio. In this manner,
each camera can be installed correctly the
first time, saving time and money.
Extending Human Capabilities
In the past, it took dozens of security
guards patrolling an area—or up to hundreds
of cameras transmitting stagnant
video to a video monitor watched by security
guards—to detect an intruder or other
incident. Video analytics handles the
tedious task of monitoring scenes to concentrate
instantly on the types of events
that security personnel need to know
about. As a result, border security workers
remotely can survey and track a wider
area with fewer people in the field.
While video analytics is an automated
function, it depends on human operators
for optimum results. When a video analytics
system detects a potential intruder, it
can create an alert. Still, it’s up to the
security operator to take appropriate
action, whether that means a closer look at
live or recently recorded video surveillance
images or the dispatching of security
officers to the site.
Taking advantage of video analytics
solutions, operators can identify and
respond to intruders or other incidents
quickly and more accurately. In this way,
video analytics functions can reduce operator
fatigue and improve both decisionmaking
and response time. For instance,
rules-based content analysis embedded in
the security cameras can provide operators
with an automated display that clearly
highlights and logs a potential intrusion
alarm. As a result, security personnel
spend less time chasing false alarms, and
the presence of specific, visually highlighted
alerts helps them take fast and
appropriate action.
Nuisance alarms are a significant
waste of time for staff who monitor borders
and perimeters. These false alarms
also can create a “boy who cried wolf”
mentality, sometimes leading security
staff to ignore, tamper with or even disable
important system functions that
deliver nuisance alarms too often. By
improving the accuracy and ease of use of
the camera system, video analytics
capabilities lead to better effectiveness
and improved motivation of security staff,
as well as more confidence in their
security tools.
A Good Picture
Regardless of the capabilities of any video
analytics solution, the software can perform
only as well as the quality of the
images. For border and perimeter security,
it is important that a camera maintains
high-quality images both during the day
and at night, performs well in bright or low
light and high-contrast lighting situations,
captures high-quality images when there’s
strong glare or reflections, maintains accurate
color in all lighting conditions and
minimizes image artifacts, such as pixel
blooming, vertical smear and color aliasing.
It’s also important that a security camera
has excellent image quality in both live
and recorded (compressed) images and
includes component parts, such as chipsets
and other electronics, that can withstand
extremes of heat, cold or vibrations.
Traditional analog charged-couple
devices struggle with providing image
quality sufficient for today’s video analytics
requirements. Constantly generating
high-quality images—regardless of lighting
conditions, temperature and other
environmental fluctuations—while avoiding
false alarms is possible only with the
latest generation of digital image sensors.
With an all-digital camera, including
embedded video analytics, there is no need
to resample and convert data from analog
to digital. Embedded video analytics takes
place on the edge of the network, rather
than after transmission to a central server.
This approach has the added advantage of
transmitting only significant events over
the network, which dramatically reduces network traffic, false alarms, time and data
storage requirements.
Video analysis depends on security
cameras with image sensors that deliver
wide dynamic range, high signal-to-noise
ratio, minimal image artifacts and accurate
color reproduction. Let’s take a closer
look at these factors:
• WDR, which is measured in decibels,
refers to a camera’s ability to capture
image details and accurate color in
both the lightest and darkest portions
of a high-contrast scene, and everything
in between, simultaneously.
• SNR measures the amount of usable
visual information—signal—compared
to the amount of noise, or
spurious, noncontent visual information,
especially random noise generated
by the image sensor or processing
in the camera.
• Image artifacts include vertical smear,
pixel blooming, color aliasing and
interlace artifacts surrounding both
still and moving objects.
• Accurate color reproduction is challenging
in lighting situations such as
bright sunlight, glare, reflections and
high-contrast lighting.
To be effective, video analytics software
requires a camera that can provide
100 dB or more dynamic range with high
SNR, minimal noise, few or no image
artifacts, accurate color and precise
details throughout all the lighting ranges
of a scene. Such a camera can deliver the
consistent, high-quality data needed to
optimize video analytics applications’
algorithms.
It is these algorithms that differentiate
between foreground and background and
between still and moving objects; that can
tell the difference between a target or
event of interest and a video artifact or
other sensor error; that can recognize the
difference between a small animal and a
human; and that can alert humans to an
out-of-place person, object or activity.
Furthermore, it is the quality of the
original camera images that enables more
accurate identification of faces, license
plates and other important details in a
scene needed to anticipate or prevent incidents,
or to provide forensic details for
effective investigation and prosecution.
Pixim’s Digital Pixel System® ultrawide
dynamic range technology delivers
image quality that is optimal for video
analytics: crisp, clear, color-accurate
images even in situations of strong backlight
and other high-contrast and difficult
lighting conditions; in all temperatures;
and with minimal image artifacts. This
technology makes it possible to record
and review high-resolution, clear images
of intruders, loiterers, escapees, or anyone
or anything else attempting to cross a
secured perimeter without permission.
Border and perimeter security poses
significant inherent challenges. Through
sophisticated video camera systems,
equipped with the latest video analytics
software and powered by all-digital
image sensing and processing chipsets,
border and perimeter security professionals
can significantly augment the skills of
their staff and potentially do a better job
of monitoring and
securing the perimeters
they must protect.
This article originally appeared in the issue of .